# Talk:Population pyramid

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## Analysis

this population pyramid also show what kind of country it is if the country is shaped like a pyramid itself then this country is a developing country since the number of babies that will grow will decrease. the decrease of the number of of babies also shows that the medical care is not good and as you go up to the working age the number of them are insufficient for the country to grow, this means that the country will grow very slowly or not grow at all.

now for developed countries the graph will look like a oval. low birth rate and low death rate. this will give more working age people. so the country will faster, but the number of old people is high. which means that the government will have to pay a big amount of pension. — Preceding unsigned comment added by 89.148.29.238 (talk) 06:55, 30 September 2006 (UTC)

## Genocides?

"Heinsohn claims that -- most genocides can be readily explained as a result of a built up youth bulge, including European colonialism, 20th century Fascism, and ongoing conflicts such as that in Darfur and terrorism."

So is colonialism equal to genocide? Did Mussolini kill that much people? I don't know about Darfur, but isn't it a bit too bold to claim terrorism being caused by youth pulge? Even if Heinsohn really said this why should we give a wrong impression by citing him?

Wikinist 07:54, 25 August 2007 (UTC)

```M. This is fun to play on iPads  — Preceding unsigned comment added by 65.255.80.96 (talk) 15:02, 21 September 2012 (UTC)
```

## Unsuitable quote

The comment that I've placed below was in the article. I don't see the relevance of the link between youth crime and islam on a page writing about population pyramids. SuzanneKn (talk) 19:17, 15 January 2008 (UTC)

Samuel Huntington has adapted youth bulge theory as the foundation of his clash of civilizations model:
"I don’t think Islam is any more violent than any other religions,[...] but the key factor is the demographic factor. Generally speaking, the people who go out and kill other people are males between the ages of 16 and 30".[1]
1. ^ 'So, are civilizations at war?', Interview with Samuel P. Huntington by Michael Steinberger, The Observer, Sunday October 21, 2001.[1]

## Age group

Wouldn't it be interesting to also put the names of the age groups, e.g. youth = up to the age of 25 according to the UN, and then babies, kids, youth, young adults, adults, active retired, elderly, or so ?--OLPC - Sven AERTS (talk) 22:15, 29 March 2009 (UTC)

## Youth bulge

This section needs some sources, and to shed the original research. It should also be balanced with a summary from Baby boom, which is a mainstream term for the expansion phase. Note that the "youth bulge" leads to what is called a "demographic dividend":[2], so this should be mentioned too. It also equates to stage 2 of the demographic transition model.

Here are some sources:

Fences and windows (talk) 14:04, 30 April 2009 (UTC)

On second thoughts - shouldn't we create Youth bulge, as it is a notable concept, and avoid overemphasising this theory on this page? Fences and windows (talk) 14:06, 30 April 2009 (UTC)

## Median age?

Not being an adept in statistics, I cannot help much to improve by contributing information here. BUT as a user, I would appreciate if someone defined how "MEDIAN AGE" is calculated before going on to use the term freely in articles about Ageing and Population Growth etc. (where I found the term). Gernot H. —Preceding unsigned comment added by GernotHir (talkcontribs) 10:13, 23 August 2009 (UTC)

I wikilinked median correctly,so now you could look it up without having to type. Mangoe (talk) 17:53, 23 August 2009 (UTC)

## Request for a diagram

A world population pyramid (structure by age and sex) would be a great addition to the article. --Eleassar my talk 21:54, 5 December 2010 (UTC)

## The labels on the pyramids are wrong, and the explanations pass over important points

In population pyramids the fertility of reproductive age classes is represented by the lowest age class. Mortality is represented by the curve of the pyramid if you lay it on its side. A population is growing if fertility is greater than mortality. The pyramids themselves do not tell you if fertility is greater than mortality, so we cant tell if a population is growing from the shape of the pyramid. In fact, the stage one pyramid is an example of a population with high fertility and high mortality, and probably is not growing. This should not be a surprise since it is the population pyramid that one would expect for what is usually represented as the situation of most societies for most of time during which population growth rates were very low. Therefore, the label "expanding" is wrong and misleading. It is doubly suspicious because the STage 2 pyramid is also labeled as "expanding". This pyramid shows a smooth rather than concave sided pyramid. This indicates that infant mortality has decreased, but we don't know if the population is expanding or contracting from the pyramid because we don't know if mortality is greater than fertility. What we do know is that countries in Stage 2 of the demographic transition have lower infant and child mortality rates and have this shape pyramid. The pyramid is associated with Stage 2 populations, but does not assure us that the population is expanding or contracting just by its shape. The stage 3 pyramid is a population with some fertility rate and a very low mortality rate until old age. The label of this one appears to be acceptable as "stationary" because the age groups are likely to remain the same through time as long as the age specific mortality rates stay the same. The article should point out that as long as mortality rates are low and fertility rates constant, that this represents a stable age distribution, but by my reasoning above, the pointy and smooth pyramids could also represent a stable age distribution too. The stage 4 pyramid appears to be labeled acceptably. There is no pyramid for countries that have had varying mortality and fertility in the last 50 years, such as China. Someone please give a reasonable mathematically sound explanation of why I am wrong or please change the article and the pyramid figure labels.

Also, I find the youth bulge hypothesis to be silly as an explanation of wars. There were European wars in spite of plagues that reduced populations. It might be advocated as a contributing cause, but it didnt cause Sweden, or any of the other countries that have passed through the demographic transition to go to war. Avram Primack (talk) 06:10, 30 October 2011 (UTC)

I presume you talk about File:DTM Pyramids.svg. I've left a note on the image creator's talk page at commons:User_talk:NikNaks#error_in_image. --Piotr Konieczny aka Prokonsul Piotrus| reply here 14:38, 26 January 2013 (UTC)
I'm afraid I don't follow the majority of this, as it seems to be mainly an issue of clarity rather than a particular error. The SVG image is simply a redrawing of this one, and I believe, and was taught in high school geography, that these were "typical" representations of pyramids for countries in those stages of the DTM. They are not meant to show every possibility - China in the paragraphs above, for instance, is not a "model" case - but just the basic structure of what one might expect them to look like in a perfect model.
The labels were not my doing, and were added later without my knowledge, and I have no idea how to edit or remove those, I'm afraid. I don't see why they are necessary at all, given that the article should do the explaining, not the image.
If there are still problems, I will monitor this page, so if there is a glaring error I don't appreciate, or if you'd like new drawings of particular cases for the article, do please say so and I'll see what I can do. NikNaks talk - gallery 14:56, 26 January 2013 (UTC)

## Zero Population Growth?

What would a population pyramid for ZPG look like? Seems to me it should approximate a Gaussian distribution with low birth rates matching death rates at the high end and a bulge in the middle at the average age. Population pyramids are a statistical description of age distribution in a particular population. Any inference of human behavior from them is nonsense. Virgil H. Soule (talk) 20:47, 20 June 2012 (UTC)